In-situ control of solid electrolyte interface for enhanced cycle performance in lithium metal batteries

Patent metadata

Field	Value
Publication number	US-2022320586-A1
Application number	US-202217703415-A
Country	US
Kind code	A1
Filing date	Mar 24, 2022
Priority date	Mar 26, 2021
Publication date	Oct 6, 2022
Grant date	—

Abstract

Some aspects of the invention are related to lithium batteries, and more specifically, to in-situ control of solid electrolyte interface for enhanced cycle performance in lithium metal batteries. In some embodiments, the electrochemical cell comprises a solid electrolyte interphase (SEI) layer that is rich in inorganic materials (e.g., LiF, Li 2 O, Li 2 CO 3 ) and has various advantageous properties (e.g., improved anode stability, etc.). Some embodiments are directed to methods of electrical energy storage and use of an electrochemical cell. In some cases, the methods comprise applying anisotropic force and/or formation voltage to a cell and forming an inorganic rich SEI layer in-situ.

First claim

What is claimed is:

1 . An electrochemical cell, comprising:
an anode comprising lithium metal, lithium alloy or combination thereof as an anode active material; an electrolyte comprising a fluorinated organic solvent; a cathode; and a solid electrolyte interphase layer disposed between the anode and the electrolyte, wherein the solid electrolyte interphase layer comprises an inorganic material comprising LiF and Li 2 CO 3 , and wherein a first ratio of fluorine atoms to oxygen atoms adjacent the electrolyte is higher than a second ratio of fluorine atoms to oxygen atoms adjacent the anode in the solid electrolyte interphase layer.

2 . An electrochemical cell, comprising:
an anode comprising lithium metal, lithium alloy or a combination thereof as an anode active material; an electrolyte comprising a fluorinated organic solvent; a cathode; and a solid electrolyte interphase layer disposed between the anode and the electrolyte, wherein the solid electrolyte interphase layer comprises LiF and has:
(1) a hardness of greater than or equal to 0.001 GPa and less than or equal to 5 GPa; and/or
(2) a porosity of greater than equal to 1% and less than or equal to 90%; and
wherein the electrochemical cell exhibits a decrease in discharge capacity of less than or equal to 10% after 100 cycles of charge and discharge with respect to a discharge capacity at the 5 th charge-discharge cycle after formation.

3 . (canceled)

4 . A method of electrical energy storage and use, comprising:
in an electrochemical cell comprising:
an anode comprising lithium metal, lithium alloy or combination thereof as an anode active material, the anode having a surface;
a cathode; and
an electrolyte comprising a fluorinated organic solvent disposed between the anode and the cathode, performing the steps of:
applying an anisotropic force to the surface of the anode; applying a formation voltage during at least one period of time during charge and/or discharge of the cell, wherein the formation voltage is greater than 4.35 V; and forming a solid electrolyte interphase layer adjacent the surface of the anode, wherein the solid electrolyte interphase layer comprises an inorganic material comprising LiF and Li 2 CO 3 .

5 - 6 . (canceled)

7 . An electrochemical cell as in claim 1 , wherein the LiF is present in an amount of at least 10 wt % in the solid electrolyte interphase layer.

8 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer further comprises Li 2 O in an amount of at least 10 wt % in the solid electrolyte interphase layer.

9 - 10 . (canceled)

11 . An electrochemical cell as in claim 1 , further comprising a separator disposed between the anode and the cathode, wherein the separator comprises pores in which the electrolyte resides.

12 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer comprises inorganic material particles having sizes of greater than or equal to 10 nm and less than or equal to 200 nm.

13 . (canceled)

14 . An electrochemical cell as in claim 1 , wherein a formation of the solid electrolyte interphase layer is associated with a formation voltage applied during at least one period of time during charge and/or discharge of the cell and/or an application of anisotropic force applied to a surface of the anode during at least one period of time during charge and/or discharge of the cell.

15 . (canceled)

16 . An electrochemical cell as in claim 14 , wherein the formation voltage is greater than 4.35 V and less than or equal to 4.9 V.

17 - 19 . (canceled)

20 . An electrochemical cell as in claim 1 , wherein the Li 2 CO 3 is formed by a reaction of CO 2 with lithium at the surface of the anode.

21 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer comprises intermixed LiF and Li 2 CO 3 .

22 . (canceled)

23 . An electrochemical cell as in claim 1 , wherein the Li 2 CO 3 is present in an amount of at least 10 wt % in the solid electrolyte interphase layer.

24 - 25 . (canceled)

26 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer further comprises one or more of lithium alkoxides, lithium oxide, lithium salts, and decomposition products of electrolyte.

28 . An electrochemical cell as in claim 1 , wherein the electrolyte comprises at least one fluorinated organic solvent selected from cyclic and linear fluorinated carbonates, fluorinated ethers, and fluorinated esters.

29 . An electrochemical cell as in claim 1 , wherein the electrolyte comprises at least one fluorinated organic solvent selected from fluoroethylene carbonate and/or difluoroethylene carbonate.

30 . (canceled)

31 . An electrochemical cell as in claim 1 , wherein the electrolyte comprises at least one non-fluorinated organic solvent, and wherein the at least one non-fluorinated organic solvent comprises an ester-based solvent and/or a cyclic or linear carbonate.

32 . (canceled)

33 . An electrochemical cell as in claim 1 , wherein the fluorinated organic solvent is present in amount of greater than or equal to 14 wt % and less than or equal to 88 wt % of a total electrolyte weight.

34 . An electrochemical cell as in claim 1 , wherein the electrolyte further comprises at least one passivating agent, and wherein the passivating agent comprises an oxalate salt.

35 - 37 . (canceled)

38 . An electrochemical cell as in claim 1 , wherein the cathode is a lithium-intercalation cathode.

39 . (canceled)

40 . An electrochemical cell as in claim 1 , wherein the first ratio of fluorine atoms to oxygen atoms adjacent the electrolyte is higher than a second ratio of fluorine atoms to oxygen atoms adjacent the anode in the solid electrolyte interphase layer based on an average ratio and/or a maximum ratio of fluorine atoms to oxygen atoms across a thickness of the solid electrolyte interphase layer.

41 - 43 . (canceled)

44 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer comprises LiF and Li 2 O in a weight ratio of greater than or equal to 1:5 and less than or equal to 2:1.

45 . An electrochemical cell as in claim 1 , wherein the solid electrolyte interphase layer has a thickness of less than or equal to 75 um.

46 - 47 . (canceled)

Assignees

• Sion Power Corp

Inventors

• Liao Zhaohui
• Scordilis-Kelley Chariclea
• Mudalige Akmeemana Anoma
• Kelley Tracy Earl
• Mikhaylik Yuriy V
• Azalia Enic
• VENEGAS Juan Gabriel

Classifications

• H01M2300/0034

  Fluorinated solvents · CPC title

• H01M4/405

  Alloys based on lithium · CPC title

• H01M10/0569 Primary

  characterised by the solvents · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M2300/004

  Three solvents · CPC title